To provide a disk device capable of being improved in vibration resistance by changing a tracking error signal to a focus error signal depending on the circumstances to detect vibrations.

The vibration detecting circuit is provided with a selector circuit 3, and is configured to detect vibrations by using the focus error signal when the tracking error signal is disturbed and the reliability of the extracted vibration component is low, and thus, the disk device capable of preventing an erroneous detection of vibrations and improving vibration resistance performance can be obtained.